package com.jjx.utils;

import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Random;

@WebServlet("/checkCode")
public class checkCode extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        int width = 100;
        int height = 50;

        //1.创建一对象，在内存中图片（验证码图片对象）
        BufferedImage bi = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        //2.美化图片
            //2.1填充背景色
        Graphics g = bi.createGraphics();//画笔对象
        g.setColor(Color.PINK);//设置画笔颜色
        g.fillRect(0,0,width,height);

        //2.2画边框
        g.setColor(Color.BLUE);
        g.drawRect(0,0,width-1,height-1);

        //2.3写验证码
        String str ="ABCDEFGHIJKLNMOPQRSTUVWSYZabcdefghijklnmopqrstuvwsyz0123456789";
        //生成随机坐标
        Random ran = new Random();
        //获取Session对象
        HttpSession session = request.getSession();
        //创建StringBuilder来存储验证码
        StringBuilder sb=new StringBuilder();
        for (int i = 1; i <=4 ; i++) {
                int index = ran.nextInt(str.length());
                //获取字符
                char c = str.charAt(index);
                sb.append(c);
                //写验证码
            g.drawString(c+"",width/5*i,height/2);
        }
        String string = sb.toString();
        session.setAttribute("checkCode",string);
        //2.4画干扰线
        g.setColor(Color.GREEN);
        //随机生成坐标点
        for (int i = 0; i <10 ; i++) {
            int x1=ran.nextInt(width);
            int x2=ran.nextInt(width);

            int y1=ran.nextInt(height);
            int y2=ran.nextInt(height);

            g.drawLine(x1,y1,x2,y2);
        }
        //3.将图片输出到页面展示
        ImageIO.write(bi,"jpg",response.getOutputStream());
    }
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    doPost(request,response);
    }
}
